Filtering a collection of samples

Abstract

A collection of samples Si, representing, for example, an image is filtered in the following manner. A distinction is made between valid samples Si+ and non-valid samples Si− on the basis of auxiliary data AUX. Filtered samples So, which are associated with the valid samples Si+, are derived exclusively on the basis of the valid samples Si+. Accordingly, it is prevented that the filtered samples, which are associated with the valid samples, are mixtures of valid and non-valid samples. Such mixtures cause distortion, in particular if the valid and non-valid samples substantially differ in value.

1. A method of filtering a collection of samples, a sample being associated with an auxiliary data item, the method comprising the steps of:
 distinguishing between valid samples and non-valid samples of the collection of samples on the basis of the associated auxiliary data item, wherein valid samples belong to one or more video objects and non-valid samples do not, and  
 computing a filtered value of a valid sample on the basis of a weighted combination of a set of values which are derived from input values of valid samples.  
 
     
     
       2. The method as claimed in  claim 1 , further comprising a step of calculating a padding value on the basis of input values of valid samples, and wherein the computing step is adapted to compute a filtered value of a valid sample on the basis of a weighted combination of values of a cluster of samples including the input value of each valid sample in the cluster and the padding value for each non-valid sample in the cluster. 
     
     
       3. The method as claimed in  claim 2 , wherein the padding value is calculated on the basis of the valid samples in the cluster. 
     
     
       4. A method as claimed in  claim 1 , wherein the cluster of samples is fixed in size. 
     
     
       5. A method as claimed in  claim 1 , wherein the samples are texture data and the auxiliary data are shape data. 
     
     
       6. A filter arrangement for filtering a collection of samples, said filter arrangement being configured to receive said samples and auxiliary data items associated with said samples, comprises:
 a multiplexing circuit for distinguishing between valid samples and non-valid samples of the collection of samples on the basis of the associated auxiliary data item, wherein valid samples belong to one or more video objects and non-valid samples do not, and  
 a filtering circuit for computing a filtered value of a valid sample on the basis of a weighted combination of a set of values which are derived from input values of valid samples.  
 
     
     
       7. The filter arrangement as claimed in  claim 6 , further comprising a padding value calculator circuit for calculating a padding value on the basis of input values of valid samples, and wherein the filtering circuit is configured to compute a filtered value of a valid sample on the basis of a weighted combination of values of a cluster of samples including the input value of each valid sample in the cluster and the padding value for each non-valid sample in the cluster.